Abstract

We present a unified approach for investigating rational reasoning about basic argument forms involving indicative conditionals, counterfactuals, and basic quantified statements within coherence-based probability logic. After introducing the rationality framework, we present an interactive view on the relation between normative and empirical work. Then, we report a new experiment which shows that people interpret indicative conditionals and counterfactuals by coherent conditional probability assertions and negate conditionals by negating their consequents. The data support the conditional probability interpretation of conditionals and the narrow-scope reading of the negation of conditionals. Finally, we argue that coherent conditional probabilities are important for probabilistic analyses of conditionals, nonmonotonic reasoning, quantified statements, and paradoxes.

Notes

Acknowledgements

We thank David Over and Giuseppe Sanfilippo as well as three anonymous referees for helpful comments on the work reported in this paper. This research was supported by the DFG Project PF 740/2-2 (awarded to Niki Pfeifer) as part of the DFG Priority Program “New Frameworks of Rationality” (SPP1516).

Appendix

The Appendix contains illustrative examples of Finnish original tasks and their English translations used in different booklets (see also Table 1).